US20140067069A1 - Artificial disc - Google Patents

Abstract

Intervertebral implants and methods of delivering the intervertebral implants include delivering an implant through the Kambin's triangle from a posterolateral approach. The intervertebral implants can include a first body portion having an open configuration and a closed configuration. The intervertebral implants can also include a second body portion having an open configuration and a closed configuration. The first body portion removably connects to the second body portion.

Description

BACKGROUND
• 1. Field
• The present application relates to medical devices and, more particularly, to a medical device and method for treating the spine.
• 2. Description of the Related Art
• The human spine is a flexible weight bearing column formed from a plurality of bones called vertebrae. There are thirty-three vertebrae, which can be grouped into one of five regions (cervical, thoracic, lumbar, sacral, and coccygeal). Moving down the spine, there are generally seven cervical vertebrae, twelve thoracic vertebrae, five lumbar vertebrae, five sacral vertebrae, and four coccygeal vertebrae. The vertebrae of the cervical, thoracic, and lumbar regions of the spine are typically separate throughout the life of an individual. In contrast, the vertebra of the sacral and coccygeal regions in an adult are fused to form two bones, the five sacral vertebrae which form the sacrum and the four coccygeal vertebrae which form the coccyx.
• In general, each vertebra contains an anterior, solid segment or body and a posterior segment or arch. The arch is generally formed of two pedicles and two laminae, supporting seven processes—four articular, two transverse, and one spinous. There are exceptions to these general characteristics of a vertebra. For example, the first cervical vertebra (atlas vertebra) has neither a body nor spinous process. In addition, the second cervical vertebra (axis vertebra) has an odontoid process, which is a strong, prominent process, shaped like a tooth, rising perpendicularly from the upper surface of the body of the axis vertebra. Further details regarding the construction of the spine may be found in such common references as Gray's Anatomy, Crown Publishers, Inc., 1977, pp. 33-54, which is herein incorporated by reference.
• The human vertebrae and associated connective elements are subjected to a variety of diseases and conditions which cause pain and disability. Among these diseases and conditions are spondylosis, spondylolisthesis, vertebral instability, spinal stenosis and degenerated, herniated, or degenerated and herniated intervertebral discs. Additionally, the vertebrae and associated connective elements are subject to injuries, including fractures and torn ligaments and surgical manipulations, including laminectomies.
• The pain and disability related to the diseases and conditions often result from the displacement of all or part of a vertebra from the remainder of the vertebral column. Over the past two decades, a variety of methods have been developed to restore the displaced vertebra to their normal position and to fix them within the vertebral column. Spinal fusion is one such method. In spinal fusion, one or more of the vertebra of the spine are united together (“fused”) so that motion no longer occurs between them. Thus, spinal fusion is the process by which the damaged disc is replaced and the spacing between the vertebrae is restored, thereby eliminating the instability and removing the pressure on neurological elements that cause pain.
• Spinal fusion can be accomplished by providing an intervertebral implant between adjacent vertebrae to recreate the natural intervertebral spacing between adjacent vertebrae. Once the implant is inserted into the intervertebral space, osteogenic substances, such as autogenous bone graft or bone allograft, can be strategically implanted adjacent the implant to prompt bone in-growth in the intervertebral space. The bone ingrowth promotes long-term fixation of the adjacent vertebrae. Various posterior fixation devices (e.g., fixation rods, screws etc.) can also be utilize to provide additional stabilization during the fusion process.
• Notwithstanding the variety of efforts in the prior art described above, these intervertebral implants and techniques are associated with another disadvantage. In particular, these techniques typically involve an open surgical procedure, which results in higher cost, lengthy in-patient hospital stays and the pain associated with open procedures. In addition, many intervertebral implants are inserted anteriorly while posterior fixation devices are inserted posteriorly. This results in additional movement of the patient. Therefore, there remains a need in the art for an improved apparatus and method for introducing an intervertebral implant.
SUMMARY
• One embodiment comprises an intervertebral implant that includes a first body portion comprising a first member, a second member, and a first joint portion. A first shaft is provide such that the first member and the second member are pivotable around the shaft. A second body portion comprises a first member, a second member, and a second joint portion. A second shaft is provided and the first member of the second body portion and the second member of the second body portion are pivotable around the shaft. The first joint portion is removably connected to the second joint portion.
• Any of the implant features described in the specification can be included in any embodiment. For example, the first and second body portions can include one or more aperture, one or more textured surfaces, and/or a bioactive coating. The one or more textured surfaces can include a ribbed surface, spikes, or other features to engage or anchor the implant into the bone and resist movement. In certain aspects, the first joint portion and the second joint portion form a ball and socket joint. In certain aspects, the implant includes one or more depressions configured for interaction with a deployment tool.
• Another embodiment comprises an intervertebral implant that includes a body portion including a first member and a second member. The first body portion includes an open configuration and a closed configuration. A shaft extends through the first body portion and the first member of the first body portion and the second member are pivotable around the shaft from the closed configuration to the open configuration. The body portion includes a motion limiting portion to limit rotational movement of first member relative to the second member when the body portion is in the open configuration.
• Any of the implant features described in the specification can be included in any embodiment. For example, the first member can be configured to translate along a central axis of the shaft. In certain aspects, one or more surfaces of the body portion can include a textured surface, one or more apertures, and/or a bioactive coating. The textured surface can include a ribbed surface, spikes, or other features to engage or anchor the implant into the bone and resist movement. In certain aspects, the body portion can include one or more depressions configured for interaction with a deployment tool. In certain aspects, the body portion can include a spring-loaded mechanism capable of transitioning the body portion from the closed configuration to the open configuration.
• Another embodiment comprises a method of performing orthopedic surgery. The method includes engaging a first body portion with a deployment tool, delivering the first body portion into an intervertebral space; and transitioning the first body portion from a closed configuration to an open configuration.
• Any of the method steps described in the specification can be included in any embodiment. For example, delivering the first body portion can include delivering the first body portion through a posterolateral approach. In certain aspects, delivering the first body portion through the posterolateral approach can include delivering the first body portion through a Kambin's triangle. In certain aspects, the method can include: engaging a second body portion with the deployment tool; delivering the second body portion into the intervertebral space; and transitioning the second body portion from a closed configuration to an open configuration. In certain aspects, the method can include connecting a first joint portion of the first body portion to a second joint portion of the second body portion.
• For purposes of summarizing the disclosure, certain aspects, advantages and features of the inventions have been described herein. It is to be understood that not necessarily any or all such advantages are achieved in accordance with any particular embodiment of the inventions disclosed herein. No aspects of this disclosure are essential or indispensable.
BRIEF DESCRIPTION OF THE DRAWINGS
• The abovementioned and other features of the inventions disclosed herein are described below with reference to the drawings of the preferred embodiments. The illustrated embodiments are intended to illustrate, but not to limit the inventions. The drawings contain the following figures:
• FIG. 1 is a lateral elevational view of a portion of a vertebral column.
• FIG. 2 is a schematic side view of Kambin's triangle.
• FIG. 3 is a perspective view of an access cannula in positioned against a vertebral column.
• FIG. 4A is a plan view of a first and second dilator tubes in a combined position.
• FIG. 4B is an enlarged detail view of the distal tip of the first and second dilator tubes shown inFIG. 4A.
• FIG. 5A is a plan view of a third dilator tube.
• FIG. 5B is an enlarged detail view of the distal tip of the third dilator tube shown inFIG. 5A.
• FIG. 6A is a side view of the access cannula shown inFIG. 3.
• FIG. 6B is an enlarged detail view of the distal tip of the access cannula shown inFIG. 6A.
• FIG. 7A is a perspective view of a dilation introducer comprising the first and second dilator tubes ofFIG. 4A, the third dilator tube ofFIG. 5A and the access cannula ofFIG. 6A.
• FIG. 7B is an enlarged detail view of the distal tip of dilation introducer shown inFIG. 7A.
• FIG. 8A is a perspective view of the dilation introducer ofFIG. 7A positioned against the spine.
• FIG. 8B is an enlarged detail view of the second dilator tube ofFIG. 7A introduced over the first dilator tube ofFIG. 7A.
• FIG. 9 is a perspective view of the dilation introducer ofFIG. 7A, with the third dilator tube introduced over the second dilator tube.
• FIGS. 10A-10D show another embodiment in which a trocar is used in place of the first dilator tube.
• FIG. 11 shows the access point before and after the foraminoplasty performed by the dilation introducer ofFIG. 7A.
• FIG. 12A is a perspective view of the dilation introducer ofFIG. 7A, with the access cannula introduced over the third dilator tube.
• FIG. 12B is a perspective view of the dilation introducer ofFIG. 7A, with the access cannula rotated to protect the exiting nerve.
• FIG. 12C is a perspective view of the dilation introducer ofFIG. 7A, with the first, second, and third dilator tubes removed, while the access cannula remains in place.
• FIG. 13 is a plan view of an intervertebral implant for delivery through the access cannula.
• FIG. 14A is a plan view of another embodiment of a first dilator tube.
• FIG. 14B is an enlarged detail view of the distal end of the first dilator tube shown inFIG. 14A.
• FIG. 14C is an enlarged detail view of the proximal end of the first dilator tube shown inFIG. 14A.
• FIG. 15A is a plan view of another embodiment of a second dilator tube.
• FIG. 15B is an enlarged detail view of the distal end of the second dilator tube shown inFIG. 15A.
• FIG. 15C is an enlarged detail view of the proximal end of the second dilator tube shown inFIG. 15A.
• FIG. 16A is a plan view of another embodiment of a third dilator tube.
• FIG. 16B is an enlarged detail view of the distal end of the third dilator tube shown inFIG. 16A.
• FIGS. 16C and 16D are enlarged detail views of the proximal end of the third dilator tube shown inFIG. 16A.
• FIG. 17A is a plan view of another embodiment of an access cannula.
• FIG. 17B is an enlarged detail view of the distal end of the access cannula shown inFIG. 17A.
• FIG. 17C is an enlarged detail view of the proximal end of the access cannula shown inFIG. 17A.
• FIG. 18A is a plan view of another embodiment of a dilation introducer comprising the first dilator tube ofFIG. 14A, the second dilator tube ofFIG. 15A, the third dilator tube ofFIG. 16A, and the access cannula ofFIG. 17A.
• FIG. 18B is an enlarged detail view of the distal end of the dilation introducer shown inFIG. 18A.
• FIG. 18C is an enlarged detail view of the proximal end of the dilation introducer shown inFIG. 18A.
• FIG. 19A is a longitudinal cross-sectional view of the dilation introducer ofFIG. 18A.
• FIG. 19B is an enlarged detail of the longitudinal cross-sectional view shown inFIG. 19A.
• FIG. 20A is a plan view of a dilation introducer equipped with neuro-monitoring leads and a neuro-monitoring needle.
• FIG. 20B is a plan view of the neuro-monitoring needle shown inFIG. 20A.
• FIG. 20C is an enlarged detail view of a distal tip of a neuro-monitoring needle ofFIG. 20A.
• FIG. 20D is an enlarged detail view of the neuro-monitoring leads shown inFIG. 20A.
• FIGS. 21-22 illustrate a first body portion of an implant in an open configuration.
• FIGS. 23-24 illustrate the first body portion in a closed configuration.
• FIGS. 25-26 illustrate a second body portion of the implant in an open configuration.
• FIG. 27 illustrates an intervertebral implant including the first body portion and the second body portion illustrated inFIGS. 21-26.
• FIG. 28 illustrates a delivery of the first body portion through an access cannula.
• FIG. 29 is a perspective view of a deployment tool according to an embodiment.
• FIG. 30 is a side cross-sectional view of the deployment tool shown inFIG. 38 wherein an expandable implant is attached to a distal end thereof.
DETAILED DESCRIPTION
• In accordance with certain embodiments disclosed herein, an improved apparatus for inserting an intervertebral implant is provided. For example, in one embodiment, the apparatus may be used to insert surgical instruments and/or one or more intervertebral implants through a minimally invasive procedure to reduce trauma to the patient and thereby enhance recovery and improve overall results. By minimally invasive, Applicant means a procedure performed percutaneously through an access device in contrast to a typically more invasive open surgical procedure.
• Certain embodiments disclosed herein are discussed in the context of an intervertebral implant and spinal fusion because of the device and methods have applicability and usefulness in such a field. The device can be used for fusion, for example, by inserting an intervertebral implant to properly space adjacent vertebrae in situations where a disc has ruptured or otherwise been damaged. “Adjacent” vertebrae can include those vertebrae originally separated only by a disc or those that are separated by intermediate vertebra and discs. Such embodiments can therefore be used to create proper disc height and spinal curvature as required in order to restore normal anatomical locations and distances. However, it is contemplated that the teachings and embodiments disclosed herein can be beneficially implemented in a variety of other operational settings, for spinal surgery and otherwise.
• Certain embodiments disclosed herein are discussed in the context of an intervertebral implant that can preserve at least some degree of motion between two adjacent vertebrae. In one arrangement, the intervertebral implant is configured to be inserted through the Kambin triangle (as described below) in a reduced cross-sectional profile. Once the implant is passed through the Kambin triangle, the implant can be converted into a second, larger cross-sectional profile in which the device can engage and maintain separation of the adjacent vertebra while still allowing least some degree of motion between two adjacent vertebrae.
• As context for the methods and devices described herein,FIG. 1 is a lateral view of avertebral column10. As shown inFIG. 1, thevertebral column10 comprises a series ofalternative vertebrae11 and fibrousintervertebral discs12 that provide axial support and movement to the upper portions of the body. Thevertebral column10 typically comprises thirty-threevertebrae11, with seven cervical (C1-C7), twelve thoracic (T1-T12), five lumbar (L1-L5), five fused sacral (S1-S5), and four fused coccygeal vertebrae.
• FIG. 2 is a schematic view of Kambin's triangle. Thisregion20 is the site of posterolateral access for spinal surgery. It can be defined as a right triangle over theintervertebral disc12 viewed dorsolaterally. The hypotenuse is the exitingnerve21, the base is the superior border of theinferior vertebra22, and the height is the traversingnerve root23. As will be explained below, in one embodiment, theintervertebral disc12 is accessed through this region by performing a foraminoplasty in which a portion of the inferior vertebra is removed such that surgical instruments or implants can be introduced at this region of the spine. In such a procedure, it is often desired to protect the exiting nerve and the traversing nerve root. Apparatuses and methods for accessing the intervertebral disc through Kambin's triangle may involve performing endoscopic foraminoplasty while protecting the nerve will be discussed in more detail below. Utilizing foraminoplasty to access the intervertebral disc through Kambin's triangle can have several advantages (e.g., less or reduced trauma to the patient) as compared to accessing the intervertebral disc posteriorly or anteriorly as is typically done in the art. In particular, surgical procedures involving posterior access often require removal of the facet joint. For example, transforaminal interbody lumbar fusion (TLIF) typically involves removal of one facet joint to create an expanded access path to the intervertebral disc. Removal of the facet joint can be very painful for the patient, and is associated with increased recovery time. In contrast, accessing the intervertebral disc through Kambin's triangle may advantageously avoid the need to remove the facet joint. As described in more detail below, endoscopic foraminoplasty may provide for expanded access to the intervertebral disc without removal of a facet joint. Sparing the facet joint may reduce patient pain and blood loss associated with the surgical procedure. In addition, sparing the facet joint can advantageously permit the use of certain posterior fixation devices which utilize the facet joint for support (e.g., trans-facet screws, trans-pedicle screws, and/or pedicle screws). In this manner, such posterior fixation devices can be used in combination with interbody devices inserted through the Kambin's triangle.
Dilation Introducer
• FIGS. 2-7B illustrate an embodiment of a dilation introducer100 that can be used to perform percutaneous orthopedic surgery. As will be described in detail below, the dilation introducer in the illustrated embodiments can comprise anaccess cannula30, and a first, second andthird dilator tubes40,45,60. While the illustrated embodiment includes first, second andthird dilator tubes40, modified embodiments can include more or less dilator tubes and/or dilator tubes with modified features. It is also anticipated that in some embodiments, theaccess cannula30 can be eliminated from the introducer or modified.
• FIG. 3 illustrates an embodiment of theaccess cannula30, which is shown in a position for performing surgery on an intervertebral disc, for instance transforaminal lumbar interbody fusion. Theaccess cannula30 in the illustrated embodiment has aninner lumen31 that allows for surgical instruments and devices to pass through it to access theintervertebral disc12. The distal tip of the cannula can be oriented such that surgical instruments have access to the intervertebral disc without contacting with the exiting nerve. The position shown inFIG. 3 can be achieved by following the method disclosed herein, discussed in more detail below.
• FIGS. 4A and 4B illustrate an embodiment of thefirst dilator tube40 andsecond dilator tube45 of the dilation introducer100. As shown, in the illustrated embodiment, thefirst dilator tube40 has adistal portion41, anouter radius42 and a firstlongitudinal lumen43. The illustratedsecond dilator tube45 has adistal portion46, an outer radius47 and a second longitudinal lumen48. As shown, the first dilator tube can be received within the lumen of the second dilator tube. Theouter radius42 of the first dilator tube can be centered around a firstlongitudinal axis44. The outer radius47 of the second dilator tube can be centered around a secondlongitudinal axis49. In the illustrated embodiment, the secondlongitudinal axis49 is laterally offset from the firstlongitudinal axis44. In the configuration shown, the outer radius of the first dilator tube is nearly equivalent to the inner radius of the second longitudinal lumen such that the first dilator tube can be slidably received within the second dilator tub. Thesecond dilator tube45 can include ahandle50 for rotating the tube independently of thefirst dilator tube40. In the illustrated embodiment, a collar can be located distal to the handle, with an outer radius larger than the outer radius of the second dilator tube, but smaller than the outer radius of the handle. In a modified embodiment, thefirst dilator tube40 can also a separate handle which can be locked together with thehandle50 of thesecond dilator tube45. In one embodiment, the first andsecond dilator tubes40,45 can locked longitudinally locked together, such that slidable movement of the first tube with respect to the second is restricted. In one embodiment, thedistal portion46 of the second dilator tube has a flattened edge. This flattened edge advantageously prevents thesecond dilator tube45 from penetrating the disc.
• FIG. 4B shows an enlarged detail view of the distal portions of the first andsecond dilator tubes40,45 ofFIG. 4A. Thedistal portion46 of thesecond dilator tube45 can have a generally semi-annular cross-section, configured such that when thefirst dilator tube40 is received within thesecond dilator tube45, the outer radial surface of thefirst dilator tube40 is partially exposed at thedistal portion46 of thesecond dilator tube45. The opening of the generally semi-annular cross-section of the second dilator tube can be oriented opposite the secondlongitudinal axis49 with respect to the firstlongitudinal axis44. Additionally, the second dilator tube can include cutting flutes orridges51 on one side, located opposite the opening of the generally semi-annular cross-section of thesecond dilator tube45. In other embodiments, the cutting flutes may be replaced with a coarse surface (e.g., knurling, sharp edges, abrasive members, etc.) which, when rotated or slid (e.g., back and forth) against bone, will create a recess therein. As noted above, other mechanisms for removing bone can be used, and the cutting flutes are shown here by way of example only. As can be seen inFIG. 4B, the inner lumen of thesecond dilator tube45 can be off-center. In this configuration, the cuttingflutes51 are further from the axis of rotation than the side opposite the cutting flutes. This is particularly advantageous for performing foraminoplasty while protecting the exiting nerve, as will be discussed in more detail below.
• Although the illustrated embodiment depicts the first and second dilator tubes as separate elements, in alternative embodiments these two tubes can be coupled formed together as one unified dilator tube with a staggered distal portion. In still other embodiments, the first dilator tube and second dilator tube may be coupled together to form a single component. The tubes may be joined by, for instance, welding, adhesive, mechanical joints, or any other appropriate means.
• In another alternative embodiment, the first dilator tube may be omitted. Instead, a Jamshidi® needle with a removable handle, or a similar device, may be used to initially define a path to the intervertebral disc. With the handle of the Jamshidi® needle removed, the second dilator tube may be advanced over the Jamshidi® needle, just as with the first dilator tube. In some embodiments, a K-wire or similar device can be inserted through the Jamshidi® needle and/or dilator tubes.
• FIGS. 5A and 5B illustrate and embodiment of thethird dilator tube60, which can be configured to be slidably introduced over thesecond dilator tube45. Thethird dilator tube60 can include adistal portion61, a thirdouter radius62 centered around a thirdlongitudinal axis63, and a thirdlongitudinal lumen64 having a thirdinner radius65. Thethird lumen64 can be configured to removably receive the second dilator tube (not shown) for slidable movement within thethird lumen64. In such a configuration, the thirdlongitudinal axis63 is parallel to and laterally offset from the secondlongitudinal axis49. Ahandle66 can allow for rotation of the third dilator tube. In one arrangement, a collar can be located distal to thehandle66, with an outer radius larger than the outer radius of thethird dilator tube45, but smaller than the outer radius of the handle.
• In some embodiments, abutton67 on thehandle66 allows for the operator to toggle between a locked and unlocked configuration. In a locked configuration, the second and third dilator tubes are unable to slide relative to one another. In an embodiment, the locked configuration permits the dilator tubes to rotate independently with respect to one another. In another embodiment, the locked configuration restrains rotational movement as well as slidable movement. Thebutton67 may comprise a generally rectangular shape with a cut-out large enough for the collar of thesecond dilator tube45 to pass therethrough. A spring located underneath thebutton67 provides upward pressure on the button. When uncompressed, the cut-out portion of the button presses firmly against the collar of thesecond dilator tube45, which may be received within thehandle66 of the third dilator tube. When uncompressed, the friction of thebutton67 against the collar inhibits movement of thethird dilator tube60 with respect to the second dilator tube. In some embodiments, the cut-out portion of the button may form a notch configured to fit within the ridge on the collar of the third dilator tube. Upon compressing thebutton67, the cut-out portion of the button may be moved away from the collar, permitting free movement of thethird dilator tube60 relative to thesecond dilator tube45.
• FIG. 5B shows an enlarged detail view of the distal portion of the third dilator tube ofFIG. 5A. Thedistal portion61 has a generally semi-annular cross-section, and cuttingflutes167 for reaming bone located opposite the opening of the semi-annular cross-section. As with the second dilator tube, in other embodiments the cutting flutes may be replaced or used in combination with a coarse or other cutting or abrading surface which, when rotated or slid against bone, will create a recess therein. As can be seen inFIG. 5B, the inner lumen of thethird dilator tube60 may be off-center. In this configuration, the cuttingflutes68 are further from the axis of rotation than the side opposite the cutting flutes. This is particularly beneficial for performing foraminoplasty while protecting the exiting nerve, as will be discussed in more detail below.
• FIGS. 6A and 6B illustrate an embodiment of the access cannula, which can be configured to be introduced over the third dilator tube (not shown). Theaccess cannula30 has adistal portion32, a fourthouter radius33 centered around a fourthlongitudinal axis34, and a fourthlongitudinal lumen31 having a fourthinner radius35. Theaccess cannula30 may be configured to removably receive the third dilator tube (not shown) for slidable movement within the third lumen. A handle allows for rotation of theaccess cannula30.
• In some embodiments, abutton37 on thehandle36 allows for the operator to toggle between a locked and unlocked configuration. In a locked configuration, third dilator tube and the access cannula are unable to slide relative to one another. In an embodiment, the locked configuration permits the dilator tubes to rotate independently with respect to one another. In another embodiment, the locked configuration restrains rotational movement as well as slidable movement. Thebutton37 may comprise a generally rectangular shape with a cut-out large enough for the collar of thethird dilator tube60 to pass therethrough. A spring located beneath thebutton37 can provide upward pressure on the button. When uncompressed, the cut-out portion of the button can press firmly against the collar of thethird dilator tube45, which may be received within the handle of theaccess cannula30. When uncompressed, the friction of thebutton37 against the collar can inhibit movement of theaccess cannula30 with respect to thethird dilator tube60. Upon compressing thebutton37, the cut-out portion of the button can be moved away from the collar, permitting free movement of theaccess cannula30 relative to thethird dilator tube60.
• FIG. 6B shows an enlarged detail view of the distal portion of the access cannula ofFIG. 6A. Thedistal portion32 can have a generally semi-annular cross-section. In the embodiment shown, the fourth longitudinal lumen may be centered with respect to the outer radius of the access cannula, in contrast to the second and third dilator tubes. In other embodiments, however, the access cannula may also have a longitudinal lumen that may be off-center with respect to the outer radius. In yet another embodiment, the access cannula need not be limited to a cylindrical outer surface. The outer surface could, for instance, have an elliptical, polygonal, or other cross-sectional shape.
• FIGS. 7A and 7B illustrate one embodiment of the dilation introducer100 in an assembled configuration. As shown, theaccess cannula30 can be positioned over thethird dilator tube60, which can be positioned over thesecond dilator tube45, which in turn can be positioned over thefirst dilator tube40. Thehandles50,151 of the first and second dilator tubes can be locked together to constrain slidable movement, but allow for thesecond dilator tube45 to rotate with respect to thefirst dilator tube40. Thethird dilator tube60 can be advanced distally until thedistal portion61 of the third dilator tube aligns with thedistal portion46 of the second dilator tube. Further, the access cannula may also be advanced so that thedistal portion32 aligns with thedistal portions46,61 of the second and third dilator tubes. The second andthird dilator tubes45,60 each have cuttingflutes51,68 on their respectivedistal portions46,61. As can be seen, the first, second, and thirdlongitudinal axes44,49,63 are each laterally offset from one another.
• In certain embodiments, the first, second and third dilator tubes along with the access cannula can be provided with additional stops that engage the buttons described above. For example, in one embodiment, notches or detents can be provided that engage the button when one tube is advanced distally and reaches a specific location (e.g., end point). In this manner, forward movement of a tube or cannula can be limited once the tube or cannula may be advanced to a desired location
• FIG. 7B shows an enlarged detail view of the dilation introducer ofFIG. 7A. Thedistal portions46,61,32 of each of the second andthird dilator tubes45,60, and of theaccess cannula30 have generally semi-annular cross-sections. Thedistal portions46,61 of the second and third dilator tubes in the illustrated embodiment can have flattened edges, to prevent penetration into the intervertebral disc as each dilator tube is advanced.
Method of Use
• FIGS. 8A-13 illustrate one embodiment of a method of performing percutaneous orthopedic surgery using the dilation introducer. With initial reference toFIG. 8A, thefirst dilator tube40 can be placed through Kambin'striangle20 until thedistal portion41 abuts or even penetrates theintervertebral disc12. In one arrangement, thesecond dilator tube45 can then be advanced over thefirst dilator tube40 until thedistal portion46 of the second dilator tube abuts but does not enter theintervertebral disc12.
• As discussed above, although the illustrated embodiment shows the first and second dilator tubes as separate elements, in alternative embodiments these two tubes may be formed together as one unified dilator tube with a staggered distal portion. In still other embodiments, the first dilator tube and second dilator tube may be coupled together to form a single component. In these alternative embodiments, the unified or coupled dilator tube may be advanced until the more distal portion abuts or penetrates the intervertebral disc.
• In another alternative embodiment, the first dilator tube may be omitted. Instead, a Jamshidi® needle with a removable handle or similar device may be used. In such an embodiment, the Jamshidi® needle may be first introduced to abut or enter the intervertebral disc, after which the handle may be removed. Optionally, a K-wire may be inserted into the Jamshidi® needle after it is in position either abutting or partially penetrating the intervertebral disc. The second dilator tube may then be advanced over the Jamshidi® needle.
• FIG. 8B shows an enlarged detail of thesecond dilator tube45 introduced over thefirst dilator tube40. Thedistal portion46 of thesecond dilator tube45 can have a semi-annular cross-section with an opening that forms a recess with respect to the leading edge of thetube45. Thesecond dilator tube45 can be oriented for advancement over thefirst dilator tube40 such that the opening of the semi-annular cross-section faces the exitingnerve21. This technique advantageously limits and/or eliminates contact with the exiting nerve. Thedistal portion46 of the second dilator tube opposite the opening of the semi-annular cross-section abuts theinferior vertebrae22. The cutting flutes (not shown) are positioned against theinferior vertebrae22. Thesecond dilator tube45 may be rotated slightly back and forth, such that the cutting flutes create a recess in theinferior vertebrae22, making room for introduction of the third dilator tube. When rotating the second dilator tube, care is taken to minimize any trauma inflicted upon the exiting nerve. Accordingly, in the illustrated embodiment, thetube45 can be used to remove bone on a side of thetube45 generally opposite of thenerve21.
• With reference now toFIG. 9, thethird dilator tube60 can be introduced over thesecond dilator tube45. In one arrangement, thedistal portion61 of thethird dilator tube60 abuts but does not enter the intervertebral disc. In the illustrated embodiment, a flattened edge of the distal portion can help ensure that thethird dilator tube60 does not penetrate the intervertebral disc or limit such penetration. As with the second dilator tube, the opening of the semi-annular cross-section of the distal portion of the third dilator tube can be positioned to face the exiting nerve (not shown). Contact between thethird dilator tube60 and the nerve can thereby be minimized or eliminated. The cutting flutes68 of the third dilator tube can be positioned opposite the opening of the semi-annular cross-section and abut theinferior vertebrae22. Thethird dilator tube60 may be rotated slightly back and forth, such that the cutting flutes create a further recess in theinferior vertebrae22, making room for introduction of the access cannula. Again, care should be taken during the rotation of the third dilator tube to ensure that the exiting nerve is not injured thereby. Accordingly, the third dilator tube can be can be used to remove bone on a side of thetube60 generally opposite of thenerve21.
• FIGS. 10A-D show an alternative method in which a trocar can be used in place of the first dilator tube. In some embodiments, the insertion point and access trajectory can first be determined. For example, a patient may lie face down on a surgical frame to facilitate a lordotic position of the lumbar spine. With aid of a lateral x-ray or other imaging system, a K-wire (or equivalent) can be laid beside the patient and placed to the depth of optimal insertion for the intervertebral implant. Intersection with the skin can be marked on the K-wire (or equivalent). With the aid of an anteroposterior x-ray or other imaging system, the K-wire (or equivalent) can be laid on top of the patient, aligned with the disc in a view that allows for the end plates to be parallel (e.g., Ferguson View or Reverse Ferguson, as applicable). The distance between the midline and the previously marked point on the K-wire can define the insertion point.
• As illustrated inFIG. 10A, a small skin incision can be made defining a trajectory into the disc can be between 45 and 55 degrees. Next, atrocar90 can be placed into the center of thedisc12 of the level to be treated, up to but not through the distal annulus. Alternatively, an 11 gauge to 18 gauge access needle can be used. As shown inFIGS. 10B-C, theinner stylet92 of the trocar (if present) can be removed while maintaining theouter sheath94 in place within thedisc12. Alternatively, a K-wire can be inserted into the disc and the outer sheath may be removed. Next, adilation introducer96 can be placed over theouter sheath94 of the trocar (or over the K-wire, if applicable). Thedilation introducer96 can be aligned so that the smooth edges are oriented towards the exiting nerve root and the foramen. In some embodiments, thedilation introducer96 can include at least second and third dilator tubes, each having cutting flutes adapted to perform foraminoplasty for improved access to the disc space. In some embodiments, thedilation introducer96 can function substantially as described elsewhere herein, except that thetrocar90 has replaced the first dilator tube. In some embodiments, the second dilator tubes may be rotated within +/−45 degrees around the longitudinal axis so that the cutting flutes do not contact the exiting nerve.
• FIG. 11 shows the access area before and after the second andthird dilator tubes45,60 are rotated to create a recess in theinferior vertebrae22. Thearea70 in the left image demarcated by a dashed line is the portion of bone that can be removed by the second andthird dilation tubes45,60. This foraminoplasty permits the access cannula to be introduced without disturbing the exitingnerve21. The method described is not limited by the precise location of the recess shown inFIG. 11. In general, a recess may be formed anywhere along the superior border of theinferior vertebrae22, in order to provide improved access for a dilation introducer.
• FIG. 12A shows theaccess cannula30 introduced over thethird dilator tube60. Thedistal portion32 of theaccess cannula30 abuts but does not enter theintervertebral disc12. In one embodiment, thedistal portion32 can be equipped with flattened edges to guard against insertion into the intervertebral disc. As with the second andthird dilator tubes45,60, the opening of the semi-annular cross-section of thedistal portion32 of theaccess cannula30 can be positioned initially to face the exiting nerve (not shown). Contact between theaccess cannula30 and the exiting nerve can thereby be minimized during insertion.
• As can be seen inFIG. 12B, theaccess cannula30 can then be rotated such that the opening of the semi-annular cross-section faces opposite the exiting nerve (not shown). Since, unlike the second andthird dilator tubes45,60, the outer surface of the access cannula is smooth, trauma to the exiting nerve may be minimized during this rotation.
• Referring now toFIG. 12C, once theaccess cannula30 is in position, which in one embodiment comprising until thedistal portion32 abuts theintervertebral disc12, thecannula30 can be rotated so that the opening of the semi-annular cross-section faces opposite the exiting nerve (not shown), the first, second, andthird dilator tubes40,45,60 may be removed. In one embodiment, rotation of thecannula30 can gently move the nerve away from the access site while also protecting the nerve as tools and devices may be inserted through thecannula30. Theaccess cannula30 can then provide anopen lumen31 through which surgical tools can be introduced to the site of theintervertebral disc12. As noted above, the positioning of theaccess cannula30 protects the exiting nerve (not shown) from coming into contact with any of the surgical tools.
• An example of a surgical tool for use through the access cannula is depicted inFIG. 13. Theintervertebral implant80 may be introduced through theaccess cannula30, and released once in position. Although a particular intervertebral implant is shown here, one of skill in the art will readily understand that any number of surgical tools may be introduced through the access cannula. For example, surgical tools to be inserted through the access cannula may include, without limitation, discectomy tools, tissue extractors, rasps, forceps, drills (e.g., trephine), rongeurs, curettes, paddle distracters, mechanical distracters, lasers, automated probes, manual probes, and plasma wands. In one embodiment of use, an opening in the disc annulus can be formed and a portion of the disc can be removed using tools advanced through theaccess cannula30. The disc space can be distracted (e.g., using paddle distracters) before and/or after theimplant80 and/or different or additional interbody devices are inserted through theaccess cannula30 and placed between the vertebral bodies to maintain spacing. In some embodiments the disc nucleus or portions thereof is removed while leaving the disc annulus.
• FIGS. 14-20D illustrate another aspect of adilation introducer1100 that can be used to perform percutaneous orthopedic surgery. The dilation introducer in this embodiment is similar in some respects to that described above. As will be described in detail below, the proximal portion of thedilation introducer1100 differs significantly from that of the dilation introducer100 described above. The dilation introducer1100 in the illustrated embodiments can comprise anaccess cannula130, and a first, second andthird dilator tubes140,145,160. While the illustrated embodiment includes first, second andthird dilator tubes140, modified embodiments can include more or less dilator tubes and/or dilator tubes with modified features. It is also anticipated that in some embodiments, theaccess cannula130 can be eliminated from the introducer or modified.
• FIGS. 14A to 14C illustrate an embodiment of thefirst dilator tube140 of thedilation introducer1100. As shown, in the illustrated embodiment, thefirst dilator tube140 may havedistal portion141, anouter radius142, and a firstlongitudinal lumen143. Theouter radius142 can be centered around firstlongitudinal axis144. Thedistal portion141 may include a taperedtip171 of the dilator tube. Theproximal portion172 of the first dilator tube may include a firstproximal head173, with a threadedportion174 distal to thegripping portion175. In some embodiments, thelongitudinal lumen143 extends through theproximal head173, such that a guidewire or K-wire may be introduced through theproximal head173 and thedilator tube140.
• FIGS. 15A to 15C illustrate an embodiment of thesecond dilator tube145. In the embodiment shown the second dilator tube has adistal portion146, and anouter radius147. The outer radius may be centered around a secondlongitudinal axis149. The second dilator tube includes a second longitudinal lumen48 with aninner radius176. Theouter radius142 of the first dilator tube may be nearly equivalent to theinner radius176 of the second dilator tube, such that thefirst dilator tube140 can be slidably received within the secondlongitudinal lumen148. Theproximal portion177 of the second dilator tube includes acollar178.
• FIG. 15B shows an enlarged detail view of the distal portion of thesecond dilator tube145. Thedistal portion146 of the second dilator tube may include a flattenededge179. This flattenededge179 advantageously prevents thesecond dilator tube145 from penetrating the intervertebral disc112. Thetip180 ofdistal portion146 can have a generally semi-annular cross-section, configured such that when thefirst dilator tube140 is received within thesecond dilator tube145, the outer radial surface of thefirst dilator tube140 is partially exposed at thedistal tip180 of thesecond dilator tube145. The opening of the generally semi-annular cross-section of the second dilator tube can be oriented opposite the secondlongitudinal axis149 with respect to thelongitudinal axis127 of the second longitudinal lumen.
• When thefirst dilator tube140 is received within thesecond dilator tube145, thelongitudinal axis127 of the second longitudinal lumen is essentially aligned with the firstlongitudinal axis144. Additionally, thesecond dilator tube145 can include cutting flutes orridges151 on one side, located opposite the opening of the generally semi-annular cross-section of thesecond dilator tube145. In other embodiments, the cuttingflutes151 may be replaced with a coarse surface (e.g., knurling, sharp edges, abrasive members, etc.) which, when rotated or slid (e.g., back and forth) against bone, will create a recess therein. As noted above, other mechanisms for removing bone can be used, and the cutting flutes are shown here by way of example only. As can be seen inFIG. 15B, theinner lumen148 of thesecond dilator tube145 can be off-center. In this configuration, the cuttingflutes151 are further from the axis of rotation than the side opposite the cutting flutes. This is particularly advantageous for performing foraminoplasty while protecting the exiting nerve, as will be discussed in more detail below.
• FIG. 15C shows an enlarged detail view of theproximal portion177 of thesecond dilator tube145. Thecollar178 includes anaperture181, which may be used in conjunction with the third dilator tube, as described in detail below. In alternative embodiments, theaperture181 may be instead replaced with a circumferentially oriented groove.
• FIGS. 16A to 16D illustrate and embodiment of thethird dilator tube160, which can be configured to be slidably introduced over thesecond dilator tube145. Thethird dilator tube160 can include adistal portion161, a thirdouter radius162 centered around a thirdlongitudinal axis163, and a thirdlongitudinal lumen164 having a thirdinner radius165 centered aroundlongitudinal axis169 that runs parallel to and laterally offset from the thirdlongitudinal axis163. Thethird lumen164 can be configured to removably receive thesecond dilator tube145 for slidable movement within thethird lumen164. In such a configuration, the secondlongitudinal axis149 essentially aligns with thelongitudinal axis169 of theinner lumen164 of thethird dilator tube160. Theproximal portion182 includes ahandle assembly183.
• FIG. 16B shows an enlarged detail view of the distal portion of the third dilator tube ofFIG. 16A. Thedistal portion161 of the third dilator tube may include a flattenededge185. This flattenededge185 advantageously prevents thethird dilator tube160 from penetrating the intervertebral disc112. Thetip184 of thedistal portion161 has a generally semi-annular cross-section, and cuttingflutes167 for reaming bone located opposite the opening of the semi-annular cross-section. As with the second dilator tube, in other embodiments the cutting flutes may be replaced or used in combination with a coarse or other cutting or abrading surface which, when rotated or slid against bone, will create a recess therein. As can be seen inFIG. 16B, thelongitudinal lumen164 of thethird dilator tube160 may be off-center. In this configuration, the cuttingflutes167 are further from the axis of rotation than the side opposite the cutting flutes. This is particularly beneficial for performing foraminoplasty while protecting the exiting nerve, as will be discussed in more detail below.
• FIGS. 16C and 16D show enlarged detail views of theproximal portion182 of thethird dilator tube160. Theproximal portion182 includes ahandle assembly183. Afirst latching button186 may be configured for constraining the movement of the third dilator tube relative to the second dilator tube, as described in more detail below. In various embodiments, thelatching button186 may constrain slidable movement, rotational movement, or both. Asecond latching button187 may be located distal thefirst latching button186, and may be configured to constrain the movement of the access cannula relative to the third dilator tube, as described in more detail below. The distal end of thehandle assembly183 includes an overhanginglip191 into which theproximal grip136 of the access cannula can be removably received. When theproximal grip136 of the access cannula is received within the overhanginglip191, thelocking pin1103 slides within the lockingpinhole1104 on theproximal grip136 of the access cannula, thereby restricting rotational movement of the access cannula relative to the third dilator tube. In various embodiments, the locking pinhole may be omitted, permitting rotation of theaccess cannula130 relative to thethird dilator tube60.
• FIGS. 17A to 17C illustrate an embodiment of theaccess cannula130, which can be configured to be introduced over thethird dilator tube145. Theaccess cannula130 has adistal portion132, a fourthlongitudinal axis134, and a fourthlongitudinal lumen131 having a fourth inner radius135. Theaccess cannula130 may be configured to removably receive the third dilator tube (not shown) for slidable movement within the third lumen. Ahandle136 allows for rotation of theaccess cannula130.
• FIG. 17B shows an enlarged detail view of the distal portion of the access cannula ofFIG. 17A. Thedistal portion132 can have a generally semi-annular cross-section. In the embodiment shown, the fourth longitudinal lumen may be centered with respect to the outer radius of the access cannula, in contrast to the second and third dilator tubes. In other embodiments, however, the access cannula may also have a longitudinal lumen that is off-center with respect to the outer radius. In yet another embodiment, the access cannula need not be limited to a cylindrical outer surface. The outer surface could, for instance, have an elliptical, polygonal, or other cross-sectional shape.
• FIG. 17C shows an enlarged detail view of the proximal portion193 of the access cannula ofFIG. 17A. Theproximal grip136 may provide additional leverage while advancing the access cannula over the third dilator tube. Theproximal grip136 includes alarger diameter portion198 and asmaller diameter portion199. Thesmaller diameter portion199 includes acircumferential channel1107 for use in interlocking with the third dilator tube, as discussed in detail below. A lockingpinhole1104 can receive thelocking pin1103 on the third dilator tube, thereby restraining rotational movement of theaccess cannula160 relative to thethird dilator tube145.
• FIGS. 18A to 18C illustrate one embodiment of thedilation introducer1100 in an assembled configuration. As shown, theaccess cannula130 can be positioned over thethird dilator tube160, which can be positioned over thesecond dilator tube145, which in turn can be positioned over thefirst dilator tube140. Thehandle assembly183 of the third dilator tube may be in a locked configuration with theproximal grip136 of the access cannula can be locked together to constrain slidable movement, but allow for theaccess cannula130 to rotate with respect to thethird dilator tube160. Additionally, thesecond dilator tube145 may be locked together with the third dilator tube to constrain slidable movement, while still allowing thesecond dilator tube145 to rotate with respect to the third dilator tube. Alternatively, the second dilator tube may be in a locked configuration preventing both slidable and rotational movement with respect to thethird dilator tube145. Thethird dilator tube60 can be advanced distally until thedistal portion161 of the third dilator tube aligns with thedistal portion46 of the second dilator tube. Further, theaccess cannula130 may also be advanced so that thedistal portion32 aligns with thedistal portions146,161 of the second and third dilator tubes. The second andthird dilator tubes145,160 each have cuttingflutes151,167 on their respectivedistal portions146,161. As can be seen, the first, second, and thirdlongitudinal axes144,149,163 are each laterally offset from one another.
• In certain embodiments, the first, second andthird dilator tubes140,145,160 along with theaccess cannula130 can be provided with additional stops that engage theproximal grip136 of the access cannula and thehandle assembly183 of the third dilator tube described above. For example, in one embodiment, notches or detents can be provided that engage theproximal grip136 or handleassembly183 when one tube is advanced distally and reaches a specific location (e.g., end point). In this manner, forward movement of a tube or cannula can be limited once the tube or cannula is advanced to a desired location
• FIG. 18B shows an enlarged detail view of the distal portion of the dilation introducer ofFIG. 18A. Thedistal portions146,161,132 of each of the second andthird dilator tubes145,160, and of theaccess cannula130 may have generally semi-annular cross-sections. Thedistal portions146,161 of the second andthird dilator tubes145,160 in the illustrated embodiment can have flattenededges179,185 to prevent penetration into the intervertebral disc as each dilator tube is advanced.
• FIG. 18C shows an enlarged detail view of the proximal portion of the dilation introducer ofFIG. 18A. Theproximal grip136 of theaccess cannula130 is shown in a locked configuration with thehandle assembly183 of thethird dilator tube160. The smaller diameter portion (not shown) may be received within the overhanginglip191 on the distal end of thehandle assembly183. Latchingbuttons186,187 constrain movement of the third dilator tube relative to the second dilator tube, and of the access cannula relative to the third dilator tube, respectively. The grippingportion175 ofproximal head173 of thefirst dilator tube140 is visible at the proximal end of the dilation introducer. As shown, the first dilator tube may be fastened to thehandle assembly183 by means of the threaded portion174 (not shown) on theproximal head173 and the threaded receiving portion190 (not shown) of thehandle assembly183. As shown, this fastening constrains both rotational and slidable movement of the first dilator tube relative to the third dilator tube. In various embodiments, the first dilator tube may be affixed to thehandle assembly183 by other means that allow for free rotational movement, free slidable movement, or both.
• Referring toFIGS. 19A and 19B, adilation introducer1100 is shown in a locked assembled configuration. The dilation introducer1100 includes afirst dilator tube140, asecond dilator tube145, athird dilator tube160, and anaccess cannula130. The first dilator tube has adistal portion141 with a taperedtip171, and aproximal portion172 having aproximal head173. In various embodiments, thefirst dilator tube140 may be cannulated, for example to allow passage of a guide wire down thelongitudinal axis143 of thefirst dilator tube140, or the first dilator tube may be without a lumen and uncannulated. Thesecond dilator tube145 has adistal tip180 with a flattenededge179, aproximal portion177 with acollar178, and alongitudinal lumen148. Thefirst dilator tube140 may be removably received within thesecond dilator tube145.
• Thethird dilator tube160 has adistal tip184 with a flattenededge185, aproximal portion182 with ahandle assembly183, and alongitudinal lumen164. Thesecond dilator tube145 may be removably received in thelongitudinal lumen164 of thethird dilator tube160 for slidable movement within thethird dilator tube160. The threadedportion174 of theproximal head173 of the first dilator tube engages with the interior threaded receivingportion190 of thehandle assembly183 of thethird dilator tube160. With the proximal head of the first dilator tube affixed to thehandle assembly183, the first andthird dilator tubes140,160 may be locked together for length and rotation. The second and third dilator tubes may be connected together in a locked configuration with afirst latching button186 disposed on thehandle assembly183 of thethird dilator tube160 and extending through afirst aperture1105 in thehandle assembly183 of thethird dilator tube160, so that thefirst latching button186 may be moveable between a radially inward locking position (arrow1101) and a radially outward unlocking position (arrow1102).
• Thedistal end196 of the first latching button may be removably received inaperture181 of thesecond dilator tube145 so as to engage and lock the second and third dilators together in the locking position. Alternatively, the latching button may be received in a circumferentially oriented groove of the second dilator tube, which may or may not extend completely around the second dilator tube. Thefirst latching button186 may be pulled radially outwardly to release thesecond dilator tube145, to allow thethird dilator tube160 to slide with respect to thesecond dilator tube145.
• Theaccess cannula130 has adistal portion161, a proximal portion193, aproximal grip136, andlongitudinal lumen164. Thethird dilator tube145 may be removably received within theaccess cannula130 for slidable movement within thelongitudinal lumen131 of theaccess cannula130. Thethird dilator tube145 and theaccess cannula130 also have a locked configuration in which theaccess cannula130 may be not permitted to slidably telescope over thethird dilator tube145.
• The proximal portion193 of theaccess cannula130 includes aproximal grip136 with alarger diameter portion198 and asmaller diameter portion199. Thesmaller diameter portion199 may be sized to fit under an overhanginglip191 of the third dilator tube, when the longitudinal axes of the third dilator tube and access cannula may be aligned. There may be a circumferentially orientedchannel1107 in the exterior of the smaller diameter portion919 for receiving adistal end197 of asecond latching button187. The circumferentially orientedchannel1107 does not need to extend completely around the exterior of thesmaller diameter portion199.
• Thethird dilator tube145 and theaccess cannula130 may be connected together in a locked configuration with thesecond latching button187 disposed on the overhanginglip191 of thehandle assembly183 of thethird dilator tube145. The second latching button extends through anaperture1106 in the overhanginglip191 of thehandle assembly183 and may be movable between a radially inward locking position (arrow194) and a radially outward unlocking position (arrow195). Thedistal end197 of thesecond latching button187 may be removably received in the channel107 located in thesmaller diameter portion199 of theaccess cannula130, in the locking position, to lock thethird dilator tube45 and theaccess cannula130 in the locked assembled configuration. Thesecond latching button187 may be pulled radially outward to release theaccess cannula130 to slide to the unlocked configuration. Furthermore, the second andthird dilator tubes140,145 may be removed together as a unit from theaccess cannula130. In other words, thefirst dilator tube140 andsecond dilator tube145 can be kept locked together and can be removed from theaccess cannula130 by unlocking thesecond latching button187 alone. An advantage of this embodiment is that the latchingbuttons186,187 may be both removable from the surgical field with the release of the third dilator tube from theaccess cannula130.
• The access cannula being free of protuberances, such as the latching buttons, is less likely to catch surgical sponges and sutures, for example, on the dilation introducer.
• Dilation Introducer with Neuro-Monitoring
• FIGS. 20A to 20D show another aspect of a dilation introducer, in which the first dilator tube may be replaced with a neuro-monitoring needle1108. The neuro-monitoring needle1108 includes awire1109 which may be enclosed by aneedle cannula1110, with thewire1109 exposed at thedistal tip1111. Theneedle cannula1110 may be surrounded bydielectric coating1112 along its length for insulation. For example, thewire1109 can comprise stainless steel and thedielectric coating1112 can comprise parylene. As noted above, aknob1115 may be located on theproximal portion1116 of the neuro-monitoring needle1108. A first neuro-monitoring lead1113 may be attached to theproximal portion177 of thesecond dilator tube145. A second neuro-monitoring lead1114 may be attached to theproximal portion183 of thethird dilator tube160.
• The neuro-monitoring needle1108 can be made from several components. Thewire1108 portion can be stainless steel coated withdielectric coating1112 of parylene. Thedistal tip1111 of thewire1109 can be exposed so that it can transmit current. Theneedle cannula1110 which covers thewire1109 can also comprise stainless steel coated with parylene. In some embodiments, this needle cannula could also be described as an exchange tube where once the wire is removed a K-wire could be placed down it and into the disc space. Thewire1109 can be attached to a handle at the proximal end ultimately protrude from the handle, serving as the electrode to attach a neuromonitoring system. In some embodiments, the proximal diameter can be parylene coated, while the rest of thewire1109 can be uncoated to transmit the current.
• Thewire1109 may comprise a conductive material, such as silver, copper, gold, aluminum, platinum, stainless steel, etc. A constant current may be applied to thewire1109. Theneedle cannula1110 may be insulated bydielectric coating1112. Although the coating shown here is dielectric, any sufficiently insulative coating may be used. Alternatively, an insulative sleeve may encase the wire. This arrangement protects theconductive wire1109 at all points except the mostdistal tip1111. As the exposed tip of thewire1109 is advanced through the tissue, it continues to be supplied with current. When thetip1111 approaches a nerve, the nerve may be stimulated. The degree of stimulation to the nerve is related to the distance between thedistal tip1111 and the nerve. Stimulation of the nerve may be measured by, e.g., visually observing the patient's leg for movement, or by measuring muscle activity through electromyography (EMG) or various other known techniques.
• Utilizing this configuration may provide the operator with added guidance as to the positioning of the first dilator tube to the surgical access point and through Kambin's triangle. With each movement, the operator may be alerted when the tip of the first dilator tube approaches or comes into contact with a nerve. The operator may use this technique alone or in conjunction with other positioning assistance techniques such as fluoroscopy and tactile feedback. The amount of current applied to thewire1109 may be varied depending on the preferred sensitivity. Naturally, the greater the current supplied, the greater nerve stimulation will result at a given distance from the nerve. In various embodiments the current applied to theconductive wire1109 may not be constant, but rather periodic or irregular. Alternatively, pulses of current may be provided only on demand from the operator.
• Although not shown here, a similar configuration may be applied to the second and third dilator tubes, and to the access cannula. Each may include a conductive wire embedded within the tube, or it may be separately attached. In either configuration, a distal tip of conductive wire may be exposed and the wire may be provided with current. As the dilator tube or access cannula is advanced through the tissue and towards the access site, nerve stimulation may be monitored as described above. The current supplied to each of the first, second, and third dilator tubes and to the access cannula may be controlled independently, so that when nerve stimulation is observed, the operator may supply current separately to each wire to determine which wire or wires are nearest to the nerve. Alternatively, current may be supplied only to one wire at any given point in the procedure. For example, the current may be supplied to the wire associated with the dilator tube or access cannula that is being moved at that point in the operation.
• In some embodiments, the second and third dilator tubes can comprise aluminum that has been anodized and then coated with parylene. Certain areas of the second and third dilator tubes can be masked from the anodization and parylene coating so that they can transmit the current. For example, the distal tips of the second and third dilator tubes can be exposed so as to conduct current therethrough. The exposed portions can be passivated to resist rusting, pitting, or corrosion. The exposed portions can be made by using a stainless steel pin pressed into the second and third dilator tubes. The pin can aid in locating the second and third dilator tubes on x-ray or fluoroscopy, and additionally can facilitate the transmission of current through the second and third dilator tubes to the area of contact. Electrode attachments for the second and third dilator tubes can be coated with parylene on the proximal larger diameter to prevent current from flowing into the user. The rest of the electrode can be uncoated, but passivated to resist rusting, pitting, or corrosion. The electrodes can attach such that the current is transmitted to the internal area of the second and third dilator tubes so that it can be transmitted distally through the exposed areas on the tips of the tubes. These tubes are attached to Radel handles, which being a polymer are also insulators. The third dilator tube can be made from stainless steel, coated with nylon or other polymer, such as Teflon, followed by a parylene coating. In embodiments in which the dilator tube comprises stainless steel, no additional x-ray marker is required.
• Although the method as described above utilizes an embodiment of the dilation introducer as shown inFIGS. 3-7B, it will be understood that the procedure may be adapted for use with various other embodiments of the dilation introducer. For instance, the dilation introducer with alternative handle assembly, as shown inFIGS. 14A-19C, may be used with appropriate modifications to the method described above. For instance, as theproximal head173 of thefirst dilator tube140 may be screwed into thehandle assembly183 of thethird dilator tube160, thefirst dilator tube140 must be unscrewed and removed prior to advancing the third dilator tube over the second dilator tube. Additionally, the latchingbuttons186,187 of thehandle assembly183 may be used to control the locking and unlocking of the dilator tubes relative to one another.
• Alternatively, the dilation introducer equipped with neuro-monitoring, as shown inFIGS. 20A-D, may be substituted. The method performed may be then similar to that described above, except that in addition the method involves monitoring nerve stimulation to assist with placement and guidance of the dilator tubes and access cannula. As described above, the current supplied to the conductive wires may be varied and controlled in order to determine the optimal location for the dilation introducer and/or access cannula.
Implant
• With respect to theimplant80 described above, theimplant80 can comprise any of a variety of types of interbody devices configured to be placed between vertebral bodies. Theimplant80 can be formed from a metal (e.g., titanium) or a non-metal material such as plastics, PEEK™, polymers, and rubbers. Further, the implant components can be made of combinations of non-metal materials (e.g., PEEK™, polymers) and metals. Theimplant80 can be configured with a fixed or substantially fixed height, length, and width as shown, for example, in the embodiment ofFIG. 13. In other embodiments, the implant can be configured to be expandable along one or more directions. For example, in certain embodiments the height of the implant can be expanded once the device advanced through the access cannula and positioned between vertebral bodies (e.g., within the disc space within the annulus).
• FIGS. 21-27 illustrate animplant500 having an first, reduced profile configuration and a second, increased profile configuration. In general, the implant can include first body portion502 (FIGS. 23 and 24) and a second portion520 (FIGS. 25 and 26) which are shown together inFIG. 27. As will be described below, in one arrangement, theimplant500 can be used to maintain separation between adjacent vertebrae while preserving at least some degree of motion between two adjacent vertebrae. In one arrangement, portions of theintervertebral implant500 can be configured to be inserted through the Kambin triangle in a first, reduced cross-sectional profile configuration, and, once a portion of theimplant500 is passed through the Kambin triangle, theimplant500 can be converted into the second, increased profile configuration in which the device can engage and maintain separation of the adjacent vertebra while still allowing least some degree of motion between two adjacent vertebrae.
• With reference toFIGS. 21 to 24, thefirst body portion502 can include afirst member504 and asecond member508. Thefirst member504 and thesecond member508 can be pivotable around afirst shaft514 from the low profile configuration, shown inFIGS. 23 and 24, to the larger profile configuration, shown inFIGS. 21 and 22. As described herein, certain features of the implant facilitate delivery through a smaller access site, such as through Kambin's triangle, while still providing structural support across a larger surface area in the intervertebral space once enlarged. As mentioned earlier, access through Kambin's triangle can reduce trauma to the patient, particularly by avoiding removal of the facet joint. Kambin's triangle also provides a viable access site for patients who are not suitable candidates for the anterior approach to spinal surgery.
• With reference toFIGS. 21 and 22, thefirst member504 can include afirst surface506, asecond surface507, andside surfaces503,505. Thesecond member508 can include afirst surface510, asecond surface509, andside surfaces511,513. One or more surfaces of thefirst member504 and thesecond member508 can include surface modifications to facilitate tissue growth and/or help the implant engage the adjacent vertebrae. The surface modifications can include, but are not limited to, textured surfaces, ridges, grooves, apertures, and/or bioactive coatings.
• Thefirst body portion502 can include one or more textured surfaces. The textured surfaces can include microscopic roughness or more easily visible protrusions. For example, one or more surfaces of the first body portion can include a ribbed surface. As shown inFIG. 21, thefirst surface506 of thefirst member504 can include a ribbed surface, and thefirst surface510 of thesecond member508 can include a ribbed surface.
• Thefirst body portion502 can include one or more apertures to facilitate osseointegration within the intervertebral space. As shown inFIG. 22, the side surfaces503,505 of thefirst member504 and the side surfaces511,513 of thesecond member508 can include one ormore apertures554. More specifically, thefirst member504 can include twoapertures554 onside surface503 and twoapertures554 onside surface505, and thesecond member508 can include two apertures onside surface511 and two apertures onside surface513. The apertures can facilitate circulation and bone growth throughout the intervertebral space and through the implant. In such implementations, the apertures can thereby facilitate integration of the implant with the surrounding materials.
• Thefirst body portion502 can be coated with one or more bioactive substances, such as antibiotics, chemotherapeutic substances, angiogenic growth factors, substances for accelerating the healing of the wound, growth hormones, anti-thrombogenic agents, bone growth accelerators or agents, and the like.
• Thefirst body portion502 can include an open configuration, shown inFIGS. 21 and 22, and a closed or low profile configuration, shown inFIG. 23. In the open or enlarged profile configuration, thefirst member504 can be perpendicular or substantially perpendicular to thesecond member508. In the closed configuration, thefirst member504 can be substantially parallel or parallel to thesecond member508. The closed configuration facilitates delivery of thefirst body portion502 through a smaller access site, such as Kambin's triangle, while the open configuration has a greater surface area to provide greater structural integrity in the intervertebral space.
• Thefirst body portion502 can include one or moremotion limiting portions518,550.Motion limiting portions518,550 can limit the rotational movement of thefirst member504 relative to thesecond member508. Themotion limiting portions518,550 can take on different configurations. For example, as shown inFIGS. 21 and 22, themotion limiting portions518,550 can permit limited clockwise and counter-clockwise rotation. As another example, the motion limiting portions will only permit limited clockwise rotation, as shown bymotion limiting portion572 inFIG. 25.
• Thefirst member504 can translate along a central axis of the first shaft. As shown inFIG. 23, when thefirst body portion502 is in the closed configuration, themotion limiting portion518 can be spaced apart frommotion limiting portion550. In the closed configuration, thefirst body portion502 is suitable for delivery through a deployment tool. In contrast, as shown inFIG. 22, when the first body portion is in the open configuration, themotion limiting portion518 can abut themotion limiting portion550. Once in the intervertebral space, thefirst body portion502 can transition from the closed configuration to the open configuration. Themotion limiting portions518,550 can prevent thefirst body portion502 from returning to the closed configuration.
• Thefirst body portion502 can transition from a closed configuration to an open configuration via a user-actuated mechanism. As another example, thefirst body portion502 can be spring-loaded. In the spring-loaded example, a tubular member, such asaccess cannula30, can restrain thefirst body portion502 to a closed configuration, but when thefirst body portion502 is delivered from the tubular member, thefirst body portion502 can transition to the open configuration. A deployment tool having forceps can also restrain thefirst body portion502 to the closed configuration. Releasing the first body portion from the deployment tool can transition thefirst body portion502 from the closed configuration to the open configuration.
• Thefirst body portion502 can also include one ormore depressions542,548 to facilitate interaction with a deployment tool.
• Thefirst body portion502 can include a metal (e.g., titanium) or a non-metal material such as plastics, PEEK™, polymers, and rubbers. Further, the implant components can be made of combinations of non-metal materials (e.g., PEEK™, polymers) and metals.
• Thefirst body portion502 can be configured with a height, length, and width suitable for delivery through the access cannula and positioning between vertebral bodies (e.g., within the disc space within the annulus). Thefirst member504 can have a uniform width, or thefirst member504 can include a tapered width. Further, thefirst member504 can include a uniform thickness, or thefirst member504 can include a tapered thickness. Thesecond member508 can have dimensions identical to or substantially similar to thefirst member504.
• As shown inFIG. 27, theimplant500 can include thefirst body portion502 and thesecond body portion520. Thesecond portion520 can be the same as or substantially similar to thefirst body portion502 discussed in reference toFIG. 21.FIGS. 25-26 illustrate asecond body portion520. Thesecond body portion520 can include one or more of thefirst body portion502 features discussed above. Generally, thesecond body portion520 can include afirst member522 and asecond member526. Thefirst member522 can include afirst surface524, asecond surface525, andside surfaces535,537. Thesecond member526 can include afirst surface528, asecond surface529, andside surfaces531,533. Thesecond body portion520 can also include asecond shaft532. Thefirst member522 and thesecond member526 can be pivotable around thesecond shaft532.
• The two-piece implant500 facilitates delivery of the implant through a smaller access site. After the implant is assembled in the intervertebral space, the two-piece implant can fill a larger space between two vertebrae than would be possible with a single component system using a similarly sized access site or access cannula.
• Thefirst body portion502 can include a firstjoint portion546, and thesecond body portion520 can include a secondjoint portion564. The firstjoint portion546 can removably connect to the secondjoint portion564. In certain aspects, the firstjoint portion546 and the secondjoint portion564 can form a ball and socket joint. The ball and socket joint permits motion along multiple axes. The firstjoint portion546 and the secondjoint portion564 can also take on any other joint configuration, including, but not limited to, a hinge joint, pivot joint, or saddle joint depending on the desirable amount of movement. In some instances, it may be desirable to limit the number of axes along which thefirst member504 is capable of moving relative to thesecond member508.
• As shown inFIG. 27, thefirst body portion502 and thesecond body portion520 can be positioned such that the textured surfaces of first andsecond body portions502,520 face outward. The outward facing, textured surfaces facilitate tissue growth between the implant and the adjacent vertebrae.
Method of Delivering an Implant
• The first body andsecond portions502,520 of theimplant500 can be delivered through the Kambin triangle utilizing the techniques and devices described above with reference toFIGS. 1-29B. Thefirst body portion502 can be delivered using any type ofdeployment tool600 capable of engaging thefirst body portion502, including, but not limited to a deployment tool having a surgical forceps feature. Thedeployment tool600 can deliver thefirst body portion502 through a posterolateral approach. The posterolateral approach can include delivering thefirst body portion502 through Kambin's triangle without removing a facet joint.
• As shown inFIG. 28, thedeployment tool600 can engage thefirst body portion502 and deliver thefirst body portion502 through thecannula30 and into the intervertebral space. Thecannula30 can gain access to the intervertebral space using any of the methods and/or devices described above.
• Once thefirst body portion502 is in the intervertebral space, the implant can transition from the closed configuration to the open configuration.Deployment tool600 can include an actuation mechanism configured to transition thefirst body portion502 from the closed configuration to the open configuration. In another arrangement, thefirst body portion502 can be spring-loaded to automatically transition to the open configuration when released from thedeployment tool600 or thecannula30.
• A filler can be injected into the intervertebral space. The filler can include any type of bone graft substance, bone cement, a carrier medium carrying bone morphogenetic proteins, or any other bone void fillers.
• Thedeployment tool600 can engage thesecond body portion520 and deliver thesecond body portion520 into the intervertebral space. Similar to thefirst body portion502, thesecond body portion520 can transition from the closed configuration to the open configuration using a user-actuated mechanism or a spring-loaded mechanism.
• Thedeployment tool600 can position thesecond body portion520 relative to thefirst body portion502. For example, thedeployment tool600 can connect the firstjoint portion546 to the secondjoint portion564, such that thesecond body portion520 is capable of controlled movement relative to thefirst body portion502. In some designs, the firstjoint portion546 and the secondjoint portion564 form a ball and socket joint.
Deployment Tool
• Referring now toFIG. 29, there is illustrated a perspective view of adeployment tool400 according to another embodiment. Thetool400 can comprise ahandle section402 and adistal engagement section404. Thehandle portion402 can be configured to be held by a user and can comprise various features to facilitate implantation and deployment of the implant.
• According to an embodiment, thehandle section402 can comprise a fixedportion410, and one or more rotatable portions, such as therotatable deployment portion412 and therotatable tethering portion414. In such an embodiment, thetethering portion414 can be used to attach the implant to thetool400 prior to insertion and deployment. Thedeployment portion412 can be used to actuate the implant and rotate the actuator shaft thereof for expanding the implant. Then, after the implant is expanded and properly placed, thetethering portion414 can again be used to untether or decouple the implant from thetool400.
• Further, thedistal engagement section404 can comprise a fixedportion420, ananti-torque component422, a tethering rod (element424 shown inFIG. 30), and a shaft actuator rod (element426 shown inFIG. 30) to facilitate engagement with and actuation of theimplant200. Theanti-torque component422 can be coupled to the fixedportion420. As described above with reference toFIGS. 21A-B, in an embodiment, theimplant200 can comprise one or more anti-torque structures250. Theanti-torque component422 can comprise one or more protrusions that engage the anti-torque structures250 to prevent movement of theimplant200 when a rotational force is applied to theactuator shaft210 via thetool400. As illustrated, theanti-torque component422 can comprise a pair of pins that extend from a distal end of thetool400. However, it is contemplated that theimplant200 andtool400 can be variously configured such that the anti-torque structures250 and theanti-torque component422 interconnect to prevent a torque being transferred to theimplant200. The generation of the rotational force will be explained in greater detail below with reference toFIG. 30, which is a side-cross sectional view of thetool400 illustrating the interrelationship of the components of thehandle section402 and thedistal engagement section404.
• For example, as illustrated inFIG. 30, the fixedportion410 of thehandle section402 can be interconnected with the fixedportion420 of thedistal engagement section404. Thedistal engagement section404 can be configured with thedeployment portion412 being coupled with theshaft actuator rod426 and thetethering portion414 being coupled with thetethering rod424. Although these portions can be coupled to each other respectively, they can move independently of each other and independently of the fixed portions. Thus, while holding the fixedportion410 of thehandle section402, thedeployment portion412 and thetethering portion414 can be moved to selectively expand or contract the implant or to attach the implant to the tool, respectively. In the illustrated embodiment, theseportions412,414 can be rotated to cause rotation of anactuator shaft210 of animplant200 engaged with thetool400.
• As shown inFIG. 30, thetether rod424 can comprise adistal engagement member430 being configured to engage a proximal end of theactuator shaft210 of theimplant200 for rotating theactuator shaft210 to thereby expand the implant from an unexpanded state to and expanded state. Thetether rod424 can be configured with thedistal engagement member430 being a threaded distal section of therod424 that can be threadably coupled to an interior threaded portion of theactuator shaft210.
• In some embodiments, thetool400 can be prepared for a single-use and can be packaged with an implant preloaded onto thetool400. This arrangement can facilitate the use of the implant and also provide a sterile implant and tool for an operation. Thus, thetool400 can be disposable after use in deploying the implant.
• Referring again toFIG. 29, an embodiment of thetool400 can also comprise anexpansion indicator gauge440 and areset button450. Theexpansion indicator gauge440 can be configured to provide a visual indication corresponding to the expansion of theimplant200. For example, thegauge440 can illustrate an exact height of theimplant200 as it is expanded or the amount of expansion. As shown inFIG. 30, thetool400 can comprise a centrally disposedslider element452 that can be in threaded engagement with athread component454 coupled to thedeployment portion412.
• In an embodiment, theslider element452 and aninternal cavity456 of the tool can be configured such that theslider element452 is provided only translational movement in the longitudinal direction of thetool400. Accordingly, as thedeployment portion412 is rotated, thethread component454 is also rotated. In such an embodiment, as thethread component454 rotates and is in engagement with theslider component452, theslider element452 can be incrementally moved from an initial position within thecavity456 in response to the rotation of thedeployment portion412. Anindicator458 can thus be longitudinally moved and viewed to allow thegauge440 to visually indicate the expansion and/or height of theimplant200. In such an embodiment, thegauge440 can comprises a transparent window through which theindicator458 on theslider element452 can be seen. In the illustrated embodiment, theindicator458 can be a marking on an exterior surface of theslider element452.
• In embodiments where thetool400 can be reused, thereset button450 can be utilized to zero out thegauge440 to a pre-expansion setting. In such an embodiment, theslider element452 can be spring-loaded, as shown with thespring460 inFIG. 30. Thereset button450 can disengage theslider element452 and thethread component454 to allow theslider element452 to be forced back to the initial position.
• Additional details and embodiments of an expandable implant can be found in U.S. Patent Application No 2008/0140207, filed Dec. 7, 2007 as U.S. patent application Ser. No. 11/952,900, the entirety of which is hereby incorporated by reference herein.
Bone Rasp
• Another example of a surgical tool for use through the access cannula is a bone rasp. A rasp tool can be configured to be inserted through theaccess cannula30 into the intervertebral disc space. The rasping tool can then be used to abrade or file the inferior surface of the superior vertebrae and/or the superior surface of the inferior vertebrae. The rasping tool can include an elongated body and a scraping component. A handle may be proximally attached to the elongated body.
• The entire assembly can be dimensioned such that the rasping tool can slide longitudinally within theaccess cannula30. In use, the rasp tool may be inserted through the access cannula until it reaches the intervertebral disc space. Using the handle, a physician may slide the elongate body and scraping component backward and forward relative to theaccess cannula30. In certain embodiments, the elongate body may freely rotate within theaccess cannula30, in order to permit the physician to rasp a surface at any desired angle. In other embodiments, the orientation of the elongate body may be fixed, such that rasping is only permitted along a predetermined angle relative to theaccess cannula30.
• In certain embodiments, the rasping tool may be expandable. For example, a rasp tool can be configured to define an unexpanded configuration. When the tool is initially inserted into the working sleeve, the tool can be positioned in the unexpanded configuration. After the tool is advanced into the intervertebral disc, the tool can be expanded to the expanded configuration.
• The tool can include an elongated body and one or more scraping components. The scraping components can each include an outer surface that is configured to scrape or create friction against the disc. For example, the outer surfaces can be generally arcuate and provide an abrasive force when in contact with the interior portion of the disc. In particular, it is contemplated that once the tool is expanded, the scraping components can rasp or scrape against the vertebral end plates of the disc from within an interior cavity formed in the disc. In this manner, the tool can prepare the surfaces of the interior of the disc by removing any additional gelatinous nucleus material, as well as smoothing out the general contours of the interior surfaces of the disc. The rasping may thereby prepare the vertebral endplates for fit with the implant as well as to promote bony fusion between the vertebrae and the implant. Due to the preparation of the interior surfaces of the disc, the placement and deployment of the implant will tend to be more effective.
• It is contemplated that the tool can comprise an expansion mechanism that allows the scraping components to move from the unexpanded to the expanded configuration. For example, the tool can be configured such that the scraping components expand from an outer dimension or height of approximately 9 mm to approximately 13 mm. In this regard, the expansion mechanism can be configured similarly to the expansion mechanisms of the implants disclosed herein, the disclosure for which is incorporated here and will not be repeated.
• Further, it is contemplated that the scraping components can comprise one or more surface structures, such as spikes, blades, apertures, etc. that allow the scraping components to not only provide an abrasive force, but that also allowed the scraping components to remove material from the disc. In this regard, as in any of the implementations of the method, a cleaning tool can be used to remove loosened, scraped, or dislodged disc material. Accordingly, in various embodiments of the methods disclosed herein, and embodiment of the tool can be used to prepare the implant site (the interior cavity of the disc) to optimize the engagement of the implant with the surfaces of the interior of the disc (the vertebral end plates).
• After the implant site has been prepared, the implant can be advanced through the access cannula and into the disc cavity. Once positioned, the implant can be expanded to its expanded configuration. For example, the implant can be expanded from approximately 9 mm to approximately 12.5 mm. Additionally, other materials or implants can then be installed prior to the removal of the access cannula and closure of the implant site.
• The specific dimensions of any of the embodiment disclosed herein can be readily varied depending upon the intended application, as will be apparent to those of skill in the art in view of the disclosure herein. Moreover, although the present inventions have been described in terms of certain preferred embodiments, other embodiments of the inventions including variations in the number of parts, dimensions, configuration and materials will be apparent to those of skill in the art in view of the disclosure herein. In addition, all features discussed in connection with any one embodiment herein can be readily adapted for use in other embodiments herein to form various combinations and sub-combinations. The use of different terms or reference numerals for similar features in different embodiments does not imply differences other than those which may be expressly set forth. Accordingly, the present inventions are intended to be described solely by reference to the appended claims, and not limited to the preferred embodiments disclosed herein.

Claims (20)

What is claimed is:

1. An intervertebral implant comprising:

a first body portion comprising a first member, a second member, and a first joint portion;

a first shaft, the first member and the second member pivotable around the shaft;

a second body portion comprising a first member, a second member, and a second joint portion; and

a second shaft, the first member of the second body portion and the second member of the second body portion pivotable around the shaft,

wherein the first joint portion removably connects to the second joint portion.

2. The implant ofclaim 1, wherein the first and second body portions include one or more apertures.

3. The implant ofclaim 1, wherein the first and second body portions include one or more textured surfaces.

4. The implant ofclaim 3, wherein the one or more textured surfaces includes a ribbed surface.

5. The implant ofclaim 1, wherein the first and second body portions include a bioactive coating.

6. The implant ofclaim 1, wherein the first joint portion and the second joint portion form a ball and socket joint.

7. The implant ofclaim 1, wherein the first and second body portions include one or more depressions configured for interaction with a deployment tool.

8. An intervertebral implant comprising:

a body portion including a first member and a second member, the first body portion including an open configuration and a closed configuration;

a shaft, the first member of the first body portion and the second member pivotable around the shaft from the closed configuration to the open configuration,

wherein the body portion includes a motion limiting portion to limit rotational movement of first member relative to the second member when the body portion is in the open configuration.

9. The implant ofclaim 8, wherein the first member is configured to translate along a central axis of the shaft.

10. The implant ofclaim 8, wherein one or more surfaces of the body portion include a textured surface.

11. The implant ofclaim 10, wherein the textured surface is a ribbed surface.

12. The implant ofclaim 8, further comprising one or more apertures.

13. The implant ofclaim 8, further comprising a bioactive coating.

14. The implant ofclaim 8, wherein the body portion includes one or more depressions configured for interaction with a deployment tool.

15. The implant ofclaim 8, wherein the body portion includes a spring-loaded mechanism capable of transitioning the body portion from the closed configuration to the open configuration.

16. A method of performing orthopedic surgery comprising:

engaging a first body portion with a deployment tool;

delivering the first body portion into an intervertebral space; and

transitioning the first body portion from a closed configuration to an open configuration.

17. The method ofclaim 16, wherein delivering the first body portion further comprises delivering the first body portion through a posterolateral approach.

18. The method ofclaim 17, wherein delivering the first body portion through the posterolateral approach further comprises delivering the first body portion through a Kambin's triangle.

19. The method ofclaim 14, further comprising:

engaging a second body portion with the deployment tool;

delivering the second body portion into the intervertebral space;

and transitioning the second body portion from a closed configuration to an open configuration.

20. The method ofclaim 19, further comprising connecting a first joint portion of the first body portion to a second joint portion of the second body portion.

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